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Android GestureDetector手势识别类

时间:2023-07-21 23:22:44

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Android GestureDetector手势识别类

为了加强鼠标响应事件,Android提供了GestureDetector手势识别类。通过GestureDetector.OnGestureListener来获取当前被触发的操作手势(Single Tap Up、Show Press、Long Press、Scroll、Down、Fling),具体包括以下几种:

boolean onDoubleTap(MotionEvent e)

解释:双击的第二下Touch down时触发

boolean onDoubleTapEvent(MotionEvent e)

解释:双击的第二下Touch down和up都会触发,可用e.getAction()区分。

boolean onDown(MotionEvent e)

解释:Touch down时触发

boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)

解释:Touch了滑动一点距离后,up时触发。

void onLongPress(MotionEvent e)

解释:Touch了不移动一直Touch down时触发

boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)

解释:Touch了滑动时触发。

void onShowPress(MotionEvent e)

解释:Touch了还没有滑动时触发

(与onDown,onLongPress比较

onDown只要Touch down一定立刻触发。

而Touchdown后过一会没有滑动先触发onShowPress再是onLongPress。

所以Touchdown后一直不滑动,onDown->onShowPress->onLongPress这个顺序触发。

boolean onSingleTapConfirmed(MotionEvent e)

boolean onSingleTapUp(MotionEvent e)

解释:上面这两个函数都是在touch down后又没有滑动(onScroll),又没有长按(onLongPress),然后Touchup时触发。

点击一下非常快的(不滑动)Touchup:

onDown->onSingleTapUp->onSingleTapConfirmed

点击一下稍微慢点的(不滑动)Touchup:

onDown->onShowPress->onSingleTapUp->onSingleTapConfirmed

使用GestureDetector需要在View中重写onTouchEvent事件,例如:

GestureDetector mGesture = null;@Overridepublic boolean onTouch(View v, MotionEvent event){// TODO Auto-generated method stubreturn mGesture.onTouchEvent(event);}

详细的测试例子如下:

package com.jiubang.android.gesturetest;import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;import android.view.GestureDetector.SimpleOnGestureListener;import android.view.View.OnTouchListener;import android.widget.Button;public class GestureActivity extends Activityimplements OnTouchListener{private Button mButton = null;GestureDetector mGesture = null;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Log.i("TEST", "onCreate");mButton = (Button)findViewById(R.id.button1);mButton.setOnTouchListener(this);mGesture = new GestureDetector(this, new GestureListener());}@Overridepublic boolean onTouch(View v, MotionEvent event){// TODO Auto-generated method stubreturn mGesture.onTouchEvent(event);}class GestureListener extends SimpleOnGestureListener{@Overridepublic boolean onDoubleTap(MotionEvent e){// TODO Auto-generated method stubLog.i("TEST", "onDoubleTap");return super.onDoubleTap(e);}@Overridepublic boolean onDown(MotionEvent e){// TODO Auto-generated method stubLog.i("TEST", "onDown");return super.onDown(e);}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY){// TODO Auto-generated method stubLog.i("TEST", "onFling:velocityX = " + velocityX + " velocityY" + velocityY);return super.onFling(e1, e2, velocityX, velocityY);}@Overridepublic void onLongPress(MotionEvent e){// TODO Auto-generated method stubLog.i("TEST", "onLongPress");super.onLongPress(e);}@Overridepublic boolean onScroll(MotionEvent e1, MotionEvent e2,float distanceX, float distanceY){// TODO Auto-generated method stubLog.i("TEST", "onScroll:distanceX = " + distanceX + " distanceY = " + distanceY);return super.onScroll(e1, e2, distanceX, distanceY);}@Overridepublic boolean onSingleTapUp(MotionEvent e){// TODO Auto-generated method stubLog.i("TEST", "onSingleTapUp");return super.onSingleTapUp(e);}}}

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